SUMMARY Detailed measurements have been made of the casing boundary layer flow before and after the nozzle blades of a single stage model air turbine. The measurements were made with the natural casing inlet boundary layer and two artificially thickened boundary layers. The results differ considerably from those usually obtained in two dimensional cascades. There was no sign of the usual second...

During the last few years, a number of numerical boundary condition schemes have been used to study various aspects of the no-slip wall condition using the lattice Boltzmann method. In this paper, a modified boundary condition method is employed to simulate the no-slip wall condition in the presence of the body force term near the wall. These conditions are based on the idea of the bounce-back ...

We propose a geometric multigrid method for solving linear systems arising from irregular boundary problems involving multiple interfaces in two and three dimensions. In this method, we adopt a matrix-free approach; i.e., we do not form the fine grid matrix explicitly and we never form nor store the coarse grid matrices, as many other robust multigrid methods do. The main idea is to construct a...

This article reports on the use of a shock tunnel to study the operation of scramjet powered configurations at sub-orbital velocities above 2 km/s. Thrust, as given by a net thrust equation, is used as a figure of merit throughout the study. After a short description of the shock tunnel used and its operating characteristics, experiments on the combustion release of heat in a constant area duct...

A computational and experimental study is reported of turbulent flow around a square-sectioned U-bend with a mean bend radius equal to 3.375 times the hydraulic diameter (DH): the duct Reynolds number is 58,000. The bend geometry is the same as that for which Chang et al. (1983) have reported extensive LDA data except that in the latter experiment the bend was preceded by some thirty hydraulic ...

In this study, we proposed a novel scheme for the implementation of the no-slip boundary condition in thelattice Boltzmann method (LBM) . In detail , we have substituted the classical bounce-back idea by the direct immersed boundary specification . In this way we construct the equilibrium density functions in such a way that it feels the no-slip boundaries . Therefore , in fact a kind of equili...

in this study, we proposed a novel scheme for the implementation of the no-slip boundary condition in thelattice boltzmann method (lbm) . in detail , we have substituted the classical bounce-back idea by the direct immersed boundary specification . in this way we construct the equilibrium density functions in such a way that it feels the no-slip boundaries . therefore , in fact a kind of equili...

Cerebral aneurysms are bulges appearing on brain arteries. The development, growth and rupture has been intensively studied using numerical tools. We present a series of studies covering many of the open questions related to the boundary conditions used in numerical simulations, namely the inlet, outlet and the wall. The effect of boundary conditions cannot be overestimated; yet it received muc...